#!/usr/bin/env ruby
# -*- coding: binary -*-
#
# $Id$
# $Revision$
#

msfbase = __FILE__
while File.symlink?(msfbase)
  msfbase = File.expand_path(File.readlink(msfbase), File.dirname(msfbase))
end

$:.unshift(File.expand_path(File.join(File.dirname(msfbase), 'lib')))
require 'msfenv'



$:.unshift(ENV['MSF_LOCAL_LIB']) if ENV['MSF_LOCAL_LIB']

require 'metasm'
require 'rex/elfparsey'
require 'rex/elfscan'
require 'rex/machparsey'
require 'rex/machscan'
require 'rex/peparsey'
require 'rex/pescan'
require 'rex/arch/x86'
require 'optparse'

def opt2i(o)
  o.index("0x")==0 ? o.hex : o.to_i
end

opt = OptionParser.new

opt.banner = "Usage: #{$PROGRAM_NAME} [mode] <options> [targets]"
opt.separator('')
opt.separator('Modes:')

worker = nil
param = {}
files = []
mode = ""

opt.on('-j', '--jump [regA,regB,regC]', 'Search for jump equivalent instructions        [PE|ELF|MACHO]') do |t|
  # take csv of register names (like eax,ebx) and convert
  # them to an array of register numbers
  mode = "jump"
  regnums = t.split(',').collect { |o|
    begin
      Rex::Arch::X86.reg_number(o)
    rescue
      puts "Invalid register \"#{o}\""
      exit(1)
    end
  }
  param['args'] = regnums
end

opt.on('-p', '--poppopret', 'Search for pop+pop+ret combinations            [PE|ELF|MACHO]') do |t|
  mode = "pop"
  param['args'] = t
end

opt.on('-r', '--regex [regex]', 'Search for regex match                         [PE|ELF|MACHO]') do |t|
  mode = "regex"
  param['args'] = t
end

opt.on('-a', '--analyze-address [address]', 'Display the code at the specified address      [PE|ELF]') do |t|
  mode = "analyze-address"
  param['args'] = opt2i(t)
end

opt.on('-b', '--analyze-offset [offset]', 'Display the code at the specified offset       [PE|ELF]') do |t|
  mode = "analyze-offset"
  param['args'] = opt2i(t)
end

opt.on('-f', '--fingerprint', 'Attempt to identify the packer/compiler        [PE]') do |t|
  mode = "fingerprint"
  param['database'] = File.join(File.dirname(msfbase), 'data', 'msfpescan', 'identify.txt')
end

opt.on('-i', '--info', 'Display detailed information about the image   [PE]') do |t|
  mode = "info"
end

opt.on('-R', '--ripper [directory]', 'Rip all module resources to disk               [PE]') do |t|
  mode = "ripper"
  param['dir'] = t
end

opt.on('--context-map [directory]', 'Generate context-map files                     [PE]') do |t|
  mode = "context"
  param['dir'] = t
end

opt.separator('')
opt.separator('Options:')

opt.on('-A', '--after [bytes]', 'Number of bytes to show after match (-a/-b)    [PE|ELF|MACHO]') do |t|
  param['after'] = opt2i(t)
end

opt.on('-B', '--before [bytes]', 'Number of bytes to show before match (-a/-b)   [PE|ELF|MACHO]') do |t|
  param['before'] = opt2i(t)
end

opt.on('-I', '--image-base [address]', 'Specify an alternate ImageBase                 [PE|ELF|MACHO]') do |t|
  param['imagebase'] = opt2i(t)
end

opt.on('-D', '--disasm', 'Disassemble the bytes at this address          [PE|ELF]') do |t|
  param['disasm'] = true
end

opt.on('-F', '--filter-addresses [regex]', 'Filter addresses based on a regular expression [PE]') do |t|
  param['filteraddr'] = t
end

opt.on_tail("-h", "--help", "Show this message") do
  $stderr.puts opt
  exit
end

begin
  opt.parse!
rescue OptionParser::InvalidOption, OptionParser::MissingArgument
  $stderr.puts "Invalid option, try -h for usage"
  exit(1)
end


if mode.empty?
  $stderr.puts "A mode must be selected"
  $stderr.puts opt
  exit(1)
end

# check if the file is a directory if it is collect all the entries
ARGV.each do |file|

  if(File.directory?(file))
    dir = Dir.open(file)
    dir.entries.each do |ent|
      path = File.join(file, ent)
      next if not File.file?(path)
      files << File.join(path)
    end
  else
    files << file
  end
end

# we need to do some work to figure out the file format
files.each do |file|
  param['file'] = file

  bin = Metasm::AutoExe.decode_file(file) if not file.empty?

  if bin.kind_of?(Metasm::PE)
    case mode
    when "jump"
      worker = Rex::PeScan::Scanner::JmpRegScanner
    when "pop"
      worker = Rex::PeScan::Scanner::PopPopRetScanner
    when "regex"
      worker = Rex::PeScan::Scanner::RegexScanner
    when "analyze-address"
      worker = Rex::PeScan::Search::DumpRVA
    when "analyze-offset"
      worker = Rex::PeScan::Search::DumpOffset
    when "fingerprint"
      worker = Rex::PeScan::Analyze::Fingerprint
    when "info"
      worker = Rex::PeScan::Analyze::Information
    when "ripper"
      worker = Rex::PeScan::Analyze::Ripper
    when "context"
      worker = Rex::PeScan::Analyze::ContextMapDumper
    else
      $stderr.puts("Mode unsupported by file format")
    end

    pe_klass = Rex::PeParsey::Pe
    begin
      pe = pe_klass.new_from_file(file, true)
    rescue ::Interrupt
      raise $!
    rescue Rex::PeParsey::FileHeaderError
      next if $!.message == "Couldn't find the PE magic!"
      raise $!
    rescue Errno::ENOENT
      $stdout.puts("File does not exist: #{file}")
      next
    rescue ::Rex::PeParsey::SkipError
      next
    rescue ::Exception => e
      $stdout.puts "[#{file}] #{e.class}: #{e}"
      next
    end

    if (param['imagebase'])
      pe.image_base = param['imagebase'];
    end

    if not worker
      $stderr.puts("A mode could not be set for this file.")
      next
    end

    o = worker.new(pe)
    o.scan(param)

    pe.close

  elsif bin.kind_of?(Metasm::ELF)
    case mode
    when "jump"
      worker = Rex::ElfScan::Scanner::JmpRegScanner
    when "pop"
      worker = Rex::ElfScan::Scanner::PopPopRetScanner
    when "regex"
      worker = Rex::ElfScan::Scanner::RegexScanner
    when "analyze-address"
      worker = Rex::ElfScan::Search::DumpRVA
    when "analyze-offset"
      worker = Rex::ElfScan::Search::DumpOffset
    else
      $stderr.puts("Mode unsupported by file format")
    end
    
    begin
      elf = Rex::ElfParsey::Elf.new_from_file(file, true)
    rescue Rex::ElfParsey::ElfHeaderError
      if $!.message == 'Invalid magic number'
        $stderr.puts("Skipping #{file}: #{$!}")
        next
      end
      raise $!
    rescue Errno::ENOENT
      $stderr.puts("File does not exist: #{file}")
      next
    end

    if (param['imagebase'])
      elf.base_addr = param['imagebase'];
    end

    if not worker
      $stderr.puts("A mode could not be set for this file.")
      next
    end
    
    o = worker.new(elf)
    o.scan(param)

    elf.close

  elsif bin.kind_of?(Metasm::MachO)
    case mode
    when "jump"
      worker = Rex::MachScan::Scanner::JmpRegScanner
    when "pop"
      worker = Rex::MachScan::Scanner::PopPopRetScanner
    when "regex"
      worker = Rex::MachScan::Scanner::RegexScanner
    else
      $stderr.puts("Mode unsupported by file format")
    end

    begin
      mach = Rex::MachParsey::Mach.new_from_file(file, true)
      o = worker.new(mach)
      o.scan(param)
      mach.close
    rescue Rex::MachParsey::MachHeaderError
      $stderr.puts("File is not a Mach-O binary, trying Fat..\n")
      begin
        fat = Rex::MachParsey::Fat.new_from_file(file, true)
        o = worker.new(fat)
        o.scan(param)
        fat.close
      rescue
        $stderr.puts("Error: " + $!.to_s)
        $stderr.puts("Skipping #{file}")
      end
    rescue Errno::ENOENT
      $stderr.puts("File does not exist: #{file}")
      next
    end
  end

  if not worker
    $stderr.puts("Unsupported file format")
    $stderr.puts("Skipping #{file}")
    next
  end
end
